2 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
4 \section[TcModule]{Typechecking a whole module}
9 tcRnStmt, tcRnExpr, tcRnType,
20 #include "HsVersions.h"
24 import {-# SOURCE #-} TcSplice ( tcSpliceDecls )
27 import DynFlags ( DynFlag(..), DynFlags(..), dopt, GhcMode(..) )
28 import StaticFlags ( opt_PprStyle_Debug )
29 import HsSyn ( HsModule(..), HsExtCore(..), HsGroup(..), LHsDecl,
30 SpliceDecl(..), HsBind(..), LHsBinds,
31 emptyRdrGroup, emptyRnGroup, appendGroups, plusHsValBinds,
32 nlHsApp, nlHsVar, pprLHsBinds )
33 import RdrHsSyn ( findSplice )
35 import PrelNames ( runMainIOName, rootMainKey, rOOT_MAIN, mAIN,
37 import RdrName ( RdrName, mkRdrUnqual, emptyGlobalRdrEnv )
38 import TcHsSyn ( zonkTopDecls )
39 import TcExpr ( tcInferRho )
41 import TcType ( tidyTopType, tcEqType )
42 import Inst ( showLIE )
43 import InstEnv ( extendInstEnvList, Instance, pprInstances, instanceDFunId )
44 import TcBinds ( tcTopBinds, tcHsBootSigs )
45 import TcDefaults ( tcDefaults )
46 import TcEnv ( tcExtendGlobalValEnv, iDFunId )
47 import TcRules ( tcRules )
48 import TcForeign ( tcForeignImports, tcForeignExports )
49 import TcInstDcls ( tcInstDecls1, tcInstDecls2 )
50 import TcIface ( tcExtCoreBindings, tcHiBootIface )
51 import MkIface ( tyThingToIfaceDecl )
52 import IfaceSyn ( checkBootDecl, IfaceExtName(..) )
53 import TcSimplify ( tcSimplifyTop )
54 import TcTyClsDecls ( tcTyAndClassDecls )
55 import LoadIface ( loadOrphanModules )
56 import RnNames ( importsFromLocalDecls, rnImports, rnExports,
57 mkRdrEnvAndImports, mkExportNameSet,
58 reportUnusedNames, reportDeprecations )
59 import RnEnv ( lookupSrcOcc_maybe )
60 import RnSource ( rnSrcDecls, rnTyClDecls, checkModDeprec )
61 import PprCore ( pprRules, pprCoreBindings )
62 import CoreSyn ( CoreRule, bindersOfBinds )
63 import ErrUtils ( Messages, mkDumpDoc, showPass )
64 import Id ( Id, mkExportedLocalId, isLocalId, idName, idType )
67 import UniqFM ( elemUFM, eltsUFM )
68 import OccName ( mkVarOccFS, plusOccEnv )
69 import Name ( Name, NamedThing(..), isExternalName, getSrcLoc, isWiredInName,
70 nameModule, nameOccName, isImplicitName, mkExternalName )
72 import TyCon ( tyConHasGenerics )
73 import SrcLoc ( srcLocSpan, Located(..), noLoc )
74 import DriverPhases ( HscSource(..), isHsBoot )
75 import HscTypes ( ModGuts(..), ModDetails(..), emptyModDetails,
76 HscEnv(..), ExternalPackageState(..),
77 IsBootInterface, noDependencies,
78 Deprecs( NoDeprecs ), plusDeprecs,
79 ForeignStubs(NoStubs),
80 TypeEnv, lookupTypeEnv, hptInstances,
81 extendTypeEnvWithIds, typeEnvIds, typeEnvTyCons, typeEnvElts,
87 import HsSyn ( HsStmtContext(..), Stmt(..), HsExpr(..),
88 HsLocalBinds(..), HsValBinds(..),
89 LStmt, LHsExpr, LHsType, mkMatch, emptyLocalBinds,
90 collectLStmtsBinders, collectLStmtBinders, nlVarPat,
91 mkFunBind, placeHolderType, noSyntaxExpr )
92 import RdrName ( GlobalRdrElt(..), globalRdrEnvElts,
93 unQualOK, lookupLocalRdrEnv, extendLocalRdrEnv )
94 import RnSource ( addTcgDUs )
95 import TcHsSyn ( mkHsDictLet, zonkTopLExpr, zonkTopBndrs )
96 import TcHsType ( kcHsType )
97 import TcMType ( zonkTcType, zonkQuantifiedTyVar )
98 import TcMatches ( tcStmts, tcDoStmt )
99 import TcSimplify ( tcSimplifyInteractive, tcSimplifyInfer )
100 import TcType ( Type, mkForAllTys, mkFunTys, mkTyConApp, tyVarsOfType, isTauTy,
101 isUnLiftedType, tyClsNamesOfDFunHead, tyClsNamesOfType, isUnitTy )
102 import TcEnv ( tcLookupTyCon, tcLookupId, tcLookupGlobal )
103 import TypeRep ( TyThing(..) )
104 import RnTypes ( rnLHsType )
105 import Inst ( tcGetInstEnvs )
106 import InstEnv ( classInstances, instEnvElts )
107 import RnExpr ( rnStmts, rnLExpr )
108 import LoadIface ( loadSysInterface )
109 import IfaceEnv ( ifaceExportNames )
110 import RnEnv ( lookupOccRn, dataTcOccs, lookupFixityRn )
111 import Id ( setIdType )
112 import MkId ( unsafeCoerceId )
113 import TyCon ( tyConName )
114 import TysWiredIn ( mkListTy, unitTy )
115 import IdInfo ( GlobalIdDetails(..) )
116 import {- Kind parts of -} Type ( Kind, eqKind )
117 import Var ( globaliseId )
118 import Name ( isBuiltInSyntax, isInternalName )
119 import OccName ( isTcOcc )
120 import NameEnv ( delListFromNameEnv )
121 import PrelNames ( iNTERACTIVE, ioTyConName, printName, itName,
122 bindIOName, thenIOName, returnIOName )
123 import HscTypes ( InteractiveContext(..),
124 ModIface(..), icPrintUnqual,
126 import BasicTypes ( Fixity, RecFlag(..) )
127 import SrcLoc ( unLoc )
128 import Data.Maybe ( isNothing )
131 import FastString ( mkFastString )
132 import Util ( sortLe )
133 import Bag ( unionBags, snocBag, emptyBag, unitBag, unionManyBags )
135 import Data.Maybe ( isJust )
140 %************************************************************************
142 Typecheck and rename a module
144 %************************************************************************
150 -> Bool -- True <=> save renamed syntax
151 -> Located (HsModule RdrName)
152 -> IO (Messages, Maybe TcGblEnv)
154 tcRnModule hsc_env hsc_src save_rn_syntax
155 (L loc (HsModule maybe_mod export_ies
156 import_decls local_decls mod_deprec))
157 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
159 let { this_pkg = thisPackage (hsc_dflags hsc_env) ;
160 this_mod = case maybe_mod of
161 Nothing -> mAIN -- 'module M where' is omitted
162 Just (L _ mod) -> mkModule this_pkg mod } ;
165 initTc hsc_env hsc_src this_mod $
168 -- Deal with imports;
169 rn_imports <- rnImports import_decls ;
170 (rdr_env, imports) <- mkRdrEnvAndImports rn_imports ;
172 let { dep_mods :: ModuleNameEnv (ModuleName, IsBootInterface)
173 ; dep_mods = imp_dep_mods imports
175 -- We want instance declarations from all home-package
176 -- modules below this one, including boot modules, except
177 -- ourselves. The 'except ourselves' is so that we don't
178 -- get the instances from this module's hs-boot file
179 ; want_instances :: ModuleName -> Bool
180 ; want_instances mod = mod `elemUFM` dep_mods
181 && mod /= moduleName this_mod
182 ; home_insts = hptInstances hsc_env want_instances
185 -- Record boot-file info in the EPS, so that it's
186 -- visible to loadHiBootInterface in tcRnSrcDecls,
187 -- and any other incrementally-performed imports
188 updateEps_ (\eps -> eps { eps_is_boot = dep_mods }) ;
190 -- Update the gbl env
192 gbl { tcg_rdr_env = plusOccEnv (tcg_rdr_env gbl) rdr_env,
193 tcg_inst_env = extendInstEnvList (tcg_inst_env gbl) home_insts,
194 tcg_imports = tcg_imports gbl `plusImportAvails` imports,
195 tcg_rn_imports = if save_rn_syntax then
199 tcg_rn_decls = if save_rn_syntax then
205 traceRn (text "rn1" <+> ppr (imp_dep_mods imports)) ;
206 -- Fail if there are any errors so far
207 -- The error printing (if needed) takes advantage
208 -- of the tcg_env we have now set
211 -- Load any orphan-module interfaces, so that
212 -- their rules and instance decls will be found
213 loadOrphanModules (imp_orphs imports) ;
215 traceRn (text "rn1a") ;
216 -- Rename and type check the declarations
217 tcg_env <- if isHsBoot hsc_src then
218 tcRnHsBootDecls local_decls
220 tcRnSrcDecls local_decls ;
221 setGblEnv tcg_env $ do {
223 traceRn (text "rn3") ;
225 -- Report the use of any deprecated things
226 -- We do this before processsing the export list so
227 -- that we don't bleat about re-exporting a deprecated
228 -- thing (especially via 'module Foo' export item)
229 -- Only uses in the body of the module are complained about
230 reportDeprecations (hsc_dflags hsc_env) tcg_env ;
232 -- Process the export list
233 rn_exports <- rnExports export_ies ;
234 let { liftM2' fn a b = do a' <- a; b' <- b; return (fn a' b') } ;
235 exports <- mkExportNameSet (isJust maybe_mod) (liftM2' (,) rn_exports export_ies) ;
237 -- Check whether the entire module is deprecated
238 -- This happens only once per module
239 let { mod_deprecs = checkModDeprec mod_deprec } ;
241 -- Add exports and deprecations to envt
242 let { final_env = tcg_env { tcg_exports = exports,
243 tcg_rn_exports = if save_rn_syntax then
246 tcg_dus = tcg_dus tcg_env `plusDU` usesOnly exports,
247 tcg_deprecs = tcg_deprecs tcg_env `plusDeprecs`
249 -- A module deprecation over-rides the earlier ones
252 -- Report unused names
253 reportUnusedNames export_ies final_env ;
255 -- Dump output and return
262 %************************************************************************
264 Type-checking external-core modules
266 %************************************************************************
269 tcRnExtCore :: HscEnv
271 -> IO (Messages, Maybe ModGuts)
272 -- Nothing => some error occurred
274 tcRnExtCore hsc_env (HsExtCore this_mod decls src_binds)
275 -- The decls are IfaceDecls; all names are original names
276 = do { showPass (hsc_dflags hsc_env) "Renamer/typechecker" ;
278 initTc hsc_env ExtCoreFile this_mod $ do {
280 let { ldecls = map noLoc decls } ;
282 -- Deal with the type declarations; first bring their stuff
283 -- into scope, then rname them, then type check them
284 tcg_env <- importsFromLocalDecls (mkFakeGroup ldecls) ;
286 setGblEnv tcg_env $ do {
288 rn_decls <- rnTyClDecls ldecls ;
291 -- Dump trace of renaming part
292 rnDump (ppr rn_decls) ;
294 -- Typecheck them all together so that
295 -- any mutually recursive types are done right
296 tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails rn_decls) ;
297 -- Make the new type env available to stuff slurped from interface files
299 setGblEnv tcg_env $ do {
301 -- Now the core bindings
302 core_binds <- initIfaceExtCore (tcExtCoreBindings src_binds) ;
306 bndrs = bindersOfBinds core_binds ;
307 my_exports = mkNameSet (map idName bndrs) ;
308 -- ToDo: export the data types also?
310 final_type_env = extendTypeEnvWithIds (tcg_type_env tcg_env) bndrs ;
312 mod_guts = ModGuts { mg_module = this_mod,
314 mg_usages = [], -- ToDo: compute usage
315 mg_dir_imps = [], -- ??
316 mg_deps = noDependencies, -- ??
317 mg_exports = my_exports,
318 mg_types = final_type_env,
319 mg_insts = tcg_insts tcg_env,
321 mg_binds = core_binds,
324 mg_rdr_env = emptyGlobalRdrEnv,
325 mg_fix_env = emptyFixityEnv,
326 mg_deprecs = NoDeprecs,
330 tcCoreDump mod_guts ;
335 mkFakeGroup decls -- Rather clumsy; lots of unused fields
336 = emptyRdrGroup { hs_tyclds = decls }
340 %************************************************************************
342 Type-checking the top level of a module
344 %************************************************************************
347 tcRnSrcDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
348 -- Returns the variables free in the decls
349 -- Reason: solely to report unused imports and bindings
351 = do { -- Load the hi-boot interface for this module, if any
352 -- We do this now so that the boot_names can be passed
353 -- to tcTyAndClassDecls, because the boot_names are
354 -- automatically considered to be loop breakers
356 boot_iface <- tcHiBootIface mod ;
358 -- Do all the declarations
359 (tc_envs, lie) <- getLIE (tc_rn_src_decls boot_iface decls) ;
361 -- tcSimplifyTop deals with constant or ambiguous InstIds.
362 -- How could there be ambiguous ones? They can only arise if a
363 -- top-level decl falls under the monomorphism
364 -- restriction, and no subsequent decl instantiates its
365 -- type. (Usually, ambiguous type variables are resolved
366 -- during the generalisation step.)
367 traceTc (text "Tc8") ;
368 inst_binds <- setEnvs tc_envs (tcSimplifyTop lie) ;
369 -- Setting the global env exposes the instances to tcSimplifyTop
370 -- Setting the local env exposes the local Ids to tcSimplifyTop,
371 -- so that we get better error messages (monomorphism restriction)
373 -- Backsubstitution. This must be done last.
374 -- Even tcSimplifyTop may do some unification.
375 traceTc (text "Tc9") ;
376 let { (tcg_env, _) = tc_envs ;
377 TcGblEnv { tcg_type_env = type_env, tcg_binds = binds,
378 tcg_rules = rules, tcg_fords = fords } = tcg_env } ;
381 (bind_ids, binds', fords', rules') <- zonkTopDecls (binds `unionBags` inst_binds)
384 let { final_type_env = extendTypeEnvWithIds type_env bind_ids
385 ; tcg_env' = tcg_env { tcg_type_env = final_type_env,
388 tcg_fords = fords' } } ;
390 -- Make the new type env available to stuff slurped from interface files
391 writeMutVar (tcg_type_env_var tcg_env) final_type_env ;
393 -- Compare the hi-boot iface (if any) with the real thing
394 dfun_binds <- checkHiBootIface tcg_env' boot_iface ;
396 return (tcg_env' { tcg_binds = tcg_binds tcg_env' `unionBags` dfun_binds })
399 tc_rn_src_decls :: ModDetails -> [LHsDecl RdrName] -> TcM (TcGblEnv, TcLclEnv)
400 -- Loops around dealing with each top level inter-splice group
401 -- in turn, until it's dealt with the entire module
402 tc_rn_src_decls boot_details ds
403 = do { let { (first_group, group_tail) = findSplice ds } ;
404 -- If ds is [] we get ([], Nothing)
406 -- Type check the decls up to, but not including, the first splice
407 tc_envs@(tcg_env,tcl_env) <- tcRnGroup boot_details first_group ;
409 -- Bale out if errors; for example, error recovery when checking
410 -- the RHS of 'main' can mean that 'main' is not in the envt for
411 -- the subsequent checkMain test
416 -- If there is no splice, we're nearly done
418 Nothing -> do { -- Last thing: check for `main'
419 tcg_env <- checkMain ;
420 return (tcg_env, tcl_env)
423 -- If there's a splice, we must carry on
424 Just (SpliceDecl splice_expr, rest_ds) -> do {
426 failWithTc (text "Can't do a top-level splice; need a bootstrapped compiler")
429 -- Rename the splice expression, and get its supporting decls
430 (rn_splice_expr, splice_fvs) <- rnLExpr splice_expr ;
431 failIfErrsM ; -- Don't typecheck if renaming failed
432 rnDump (ppr rn_splice_expr) ;
434 -- Execute the splice
435 spliced_decls <- tcSpliceDecls rn_splice_expr ;
437 -- Glue them on the front of the remaining decls and loop
438 setGblEnv (tcg_env `addTcgDUs` usesOnly splice_fvs) $
439 tc_rn_src_decls boot_details (spliced_decls ++ rest_ds)
444 %************************************************************************
446 Compiling hs-boot source files, and
447 comparing the hi-boot interface with the real thing
449 %************************************************************************
452 tcRnHsBootDecls :: [LHsDecl RdrName] -> TcM TcGblEnv
453 tcRnHsBootDecls decls
454 = do { let { (first_group, group_tail) = findSplice decls }
457 Just stuff -> spliceInHsBootErr stuff
460 -- Rename the declarations
461 ; (tcg_env, rn_group) <- rnTopSrcDecls first_group
462 ; setGblEnv tcg_env $ do {
464 -- Todo: check no foreign decls, no rules, no default decls
466 -- Typecheck type/class decls
467 ; traceTc (text "Tc2")
468 ; let tycl_decls = hs_tyclds rn_group
469 ; tcg_env <- checkNoErrs (tcTyAndClassDecls emptyModDetails tycl_decls)
470 ; setGblEnv tcg_env $ do {
472 -- Typecheck instance decls
473 ; traceTc (text "Tc3")
474 ; (tcg_env, inst_infos, _binds) <- tcInstDecls1 tycl_decls (hs_instds rn_group)
475 ; setGblEnv tcg_env $ do {
477 -- Typecheck value declarations
478 ; traceTc (text "Tc5")
479 ; val_ids <- tcHsBootSigs (hs_valds rn_group)
482 -- No simplification or zonking to do
483 ; traceTc (text "Tc7a")
484 ; gbl_env <- getGblEnv
486 -- Make the final type-env
487 -- Include the dfun_ids so that their type sigs get
488 -- are written into the interface file
489 ; let { type_env0 = tcg_type_env gbl_env
490 ; type_env1 = extendTypeEnvWithIds type_env0 val_ids
491 ; type_env2 = extendTypeEnvWithIds type_env1 dfun_ids
492 ; dfun_ids = map iDFunId inst_infos }
493 ; return (gbl_env { tcg_type_env = type_env2 })
496 spliceInHsBootErr (SpliceDecl (L loc _), _)
497 = addErrAt loc (ptext SLIT("Splices are not allowed in hs-boot files"))
500 Once we've typechecked the body of the module, we want to compare what
501 we've found (gathered in a TypeEnv) with the hi-boot details (if any).
504 checkHiBootIface :: TcGblEnv -> ModDetails -> TcM (LHsBinds Id)
505 -- Compare the hi-boot file for this module (if there is one)
506 -- with the type environment we've just come up with
507 -- In the common case where there is no hi-boot file, the list
508 -- of boot_names is empty.
510 -- The bindings we return give bindings for the dfuns defined in the
511 -- hs-boot file, such as $fbEqT = $fEqT
514 (TcGblEnv { tcg_insts = local_insts, tcg_type_env = local_type_env })
515 (ModDetails { md_insts = boot_insts, md_types = boot_type_env })
516 = do { traceTc (text "checkHiBootIface" <+> (ppr boot_type_env $$ ppr boot_insts)) ;
517 ; mapM_ check_one (typeEnvElts boot_type_env)
518 ; dfun_binds <- mapM check_inst boot_insts
519 ; return (unionManyBags dfun_binds) }
524 | Just real_thing <- lookupTypeEnv local_type_env name
525 = do { let boot_decl = tyThingToIfaceDecl ext_nm boot_thing
526 real_decl = tyThingToIfaceDecl ext_nm real_thing
527 ; checkTc (checkBootDecl boot_decl real_decl)
528 (bootMisMatch boot_thing boot_decl real_decl) }
529 -- The easiest way to check compatibility is to convert to
530 -- iface syntax, where we already have good comparison functions
532 = addErrTc (missingBootThing boot_thing)
534 name = getName boot_thing
536 ext_nm name = ExtPkg (nameModule name) (nameOccName name)
537 -- Just enough to compare; no versions etc needed
539 no_check name = isWiredInName name -- No checking for wired-in names. In particular,
540 -- 'error' is handled by a rather gross hack
541 -- (see comments in GHC.Err.hs-boot)
542 || name `elem` dfun_names
543 || isImplicitName name -- Has a parent, which we'll check
545 dfun_names = map getName boot_insts
548 = case [dfun | inst <- local_insts,
549 let dfun = instanceDFunId inst,
550 idType dfun `tcEqType` boot_inst_ty ] of
551 [] -> do { addErrTc (instMisMatch boot_inst); return emptyBag }
552 (dfun:_) -> return (unitBag $ noLoc $ VarBind local_boot_dfun (nlHsVar dfun))
554 boot_dfun = instanceDFunId boot_inst
555 boot_inst_ty = idType boot_dfun
556 local_boot_dfun = mkExportedLocalId (idName boot_dfun) boot_inst_ty
559 missingBootThing thing
560 = ppr thing <+> ptext SLIT("is defined in the hs-boot file, but not in the module")
561 bootMisMatch thing boot_decl real_decl
562 = ppr thing <+> ptext SLIT("has conflicting definitions in the module and its hs-boot file")
565 2 (ptext SLIT("is defined in the hs-boot file, but not in the module"))
569 %************************************************************************
571 Type-checking the top level of a module
573 %************************************************************************
575 tcRnGroup takes a bunch of top-level source-code declarations, and
577 * gets supporting declarations from interface files
580 * and augments the TcGblEnv with the results
582 In Template Haskell it may be called repeatedly for each group of
583 declarations. It expects there to be an incoming TcGblEnv in the
584 monad; it augments it and returns the new TcGblEnv.
587 tcRnGroup :: ModDetails -> HsGroup RdrName -> TcM (TcGblEnv, TcLclEnv)
588 -- Returns the variables free in the decls, for unused-binding reporting
589 tcRnGroup boot_details decls
590 = do { -- Rename the declarations
591 (tcg_env, rn_decls) <- rnTopSrcDecls decls ;
592 setGblEnv tcg_env $ do {
594 -- Typecheck the declarations
595 tcTopSrcDecls boot_details rn_decls
598 ------------------------------------------------
599 rnTopSrcDecls :: HsGroup RdrName -> TcM (TcGblEnv, HsGroup Name)
601 = do { -- Bring top level binders into scope
602 tcg_env <- importsFromLocalDecls group ;
603 setGblEnv tcg_env $ do {
605 failIfErrsM ; -- No point in continuing if (say) we have duplicate declarations
607 -- Rename the source decls
608 (tcg_env, rn_decls) <- rnSrcDecls group ;
611 -- save the renamed syntax, if we want it
613 | Just grp <- tcg_rn_decls tcg_env
614 = tcg_env{ tcg_rn_decls = Just (appendGroups grp rn_decls) }
618 -- Dump trace of renaming part
619 rnDump (ppr rn_decls) ;
621 return (tcg_env', rn_decls)
624 ------------------------------------------------
625 tcTopSrcDecls :: ModDetails -> HsGroup Name -> TcM (TcGblEnv, TcLclEnv)
626 tcTopSrcDecls boot_details
627 (HsGroup { hs_tyclds = tycl_decls,
628 hs_instds = inst_decls,
629 hs_fords = foreign_decls,
630 hs_defds = default_decls,
631 hs_ruleds = rule_decls,
632 hs_valds = val_binds })
633 = do { -- Type-check the type and class decls, and all imported decls
634 -- The latter come in via tycl_decls
635 traceTc (text "Tc2") ;
637 tcg_env <- checkNoErrs (tcTyAndClassDecls boot_details tycl_decls) ;
638 -- tcTyAndClassDecls recovers internally, but if anything gave rise to
639 -- an error we'd better stop now, to avoid a cascade
641 -- Make these type and class decls available to stuff slurped from interface files
642 writeMutVar (tcg_type_env_var tcg_env) (tcg_type_env tcg_env) ;
645 setGblEnv tcg_env $ do {
646 -- Source-language instances, including derivings,
647 -- and import the supporting declarations
648 traceTc (text "Tc3") ;
649 (tcg_env, inst_infos, deriv_binds) <- tcInstDecls1 tycl_decls inst_decls ;
650 setGblEnv tcg_env $ do {
652 -- Foreign import declarations next. No zonking necessary
653 -- here; we can tuck them straight into the global environment.
654 traceTc (text "Tc4") ;
655 (fi_ids, fi_decls) <- tcForeignImports foreign_decls ;
656 tcExtendGlobalValEnv fi_ids $ do {
658 -- Default declarations
659 traceTc (text "Tc4a") ;
660 default_tys <- tcDefaults default_decls ;
661 updGblEnv (\gbl -> gbl { tcg_default = default_tys }) $ do {
663 -- Value declarations next
664 -- We also typecheck any extra binds that came out
665 -- of the "deriving" process (deriv_binds)
666 traceTc (text "Tc5") ;
667 (tc_val_binds, tcl_env) <- tcTopBinds (val_binds `plusHsValBinds` deriv_binds) ;
668 setLclTypeEnv tcl_env $ do {
670 -- Second pass over class and instance declarations,
671 traceTc (text "Tc6") ;
672 (inst_binds, tcl_env) <- tcInstDecls2 tycl_decls inst_infos ;
673 showLIE (text "after instDecls2") ;
676 -- They need to be zonked, so we return them
677 traceTc (text "Tc7") ;
678 (foe_binds, foe_decls) <- tcForeignExports foreign_decls ;
681 rules <- tcRules rule_decls ;
684 traceTc (text "Tc7a") ;
685 tcg_env <- getGblEnv ;
686 let { all_binds = tc_val_binds `unionBags`
687 inst_binds `unionBags`
690 -- Extend the GblEnv with the (as yet un-zonked)
691 -- bindings, rules, foreign decls
692 tcg_env' = tcg_env { tcg_binds = tcg_binds tcg_env `unionBags` all_binds,
693 tcg_rules = tcg_rules tcg_env ++ rules,
694 tcg_fords = tcg_fords tcg_env ++ foe_decls ++ fi_decls } } ;
695 return (tcg_env', tcl_env)
700 %************************************************************************
704 %************************************************************************
707 checkMain :: TcM TcGblEnv
708 -- If we are in module Main, check that 'main' is defined.
710 = do { ghc_mode <- getGhcMode ;
711 tcg_env <- getGblEnv ;
713 let { main_mod = mainModIs dflags ;
714 main_fn = case mainFunIs dflags of {
715 Just fn -> mkRdrUnqual (mkVarOccFS (mkFastString fn)) ;
716 Nothing -> main_RDR_Unqual } } ;
718 check_main ghc_mode tcg_env main_mod main_fn
722 check_main ghc_mode tcg_env main_mod main_fn
724 = traceTc (text "checkMain not" <+> ppr main_mod <+> ppr mod) >>
728 = addErrCtxt mainCtxt $
729 do { mb_main <- lookupSrcOcc_maybe main_fn
730 -- Check that 'main' is in scope
731 -- It might be imported from another module!
733 Nothing -> do { traceTc (text "checkMain fail" <+> ppr main_mod <+> ppr main_fn)
737 { traceTc (text "checkMain found" <+> ppr main_mod <+> ppr main_fn)
738 ; let { rhs = nlHsApp (nlHsVar runMainIOName) (nlHsVar main_name) }
739 -- :Main.main :: IO () = runMainIO main
741 ; (main_expr, ty) <- setSrcSpan (srcLocSpan (getSrcLoc main_name)) $
744 -- The function that the RTS invokes is always :Main.main,
745 -- which we call root_main_id.
746 -- (Because GHC allows the user to have a module not called
747 -- Main as the main module, we can't rely on the main function
748 -- being called "Main.main". That's why root_main_id has a fixed
750 -- We also make root_main_id an implicit Id, by making main_name
751 -- its parent (hence (Just main_name)). That has the effect
752 -- of preventing its type and unfolding from getting out into
753 -- the interface file. Otherwise we can end up with two defns
754 -- for 'main' in the interface file!
756 ; let { root_main_name = mkExternalName rootMainKey rOOT_MAIN
757 (mkVarOccFS FSLIT("main"))
758 (Just main_name) (getSrcLoc main_name)
759 ; root_main_id = mkExportedLocalId root_main_name ty
760 ; main_bind = noLoc (VarBind root_main_id main_expr) }
762 ; return (tcg_env { tcg_binds = tcg_binds tcg_env
764 tcg_dus = tcg_dus tcg_env
765 `plusDU` usesOnly (unitFV main_name)
766 -- Record the use of 'main', so that we don't
767 -- complain about it being defined but not used
771 mod = tcg_mod tcg_env
773 complain_no_main | ghc_mode == Interactive = return ()
774 | otherwise = failWithTc noMainMsg
775 -- In interactive mode, don't worry about the absence of 'main'
776 -- In other modes, fail altogether, so that we don't go on
777 -- and complain a second time when processing the export list.
779 mainCtxt = ptext SLIT("When checking the type of the main function") <+> quotes (ppr main_fn)
780 noMainMsg = ptext SLIT("The main function") <+> quotes (ppr main_fn)
781 <+> ptext SLIT("is not defined in module") <+> quotes (ppr main_mod)
784 %*********************************************************
788 %*********************************************************
792 setInteractiveContext :: HscEnv -> InteractiveContext -> TcRn a -> TcRn a
793 setInteractiveContext hsc_env icxt thing_inside
795 -- Initialise the tcg_inst_env with instances
796 -- from all home modules. This mimics the more selective
797 -- call to hptInstances in tcRnModule
798 dfuns = hptInstances hsc_env (\mod -> True)
800 updGblEnv (\env -> env {
801 tcg_rdr_env = ic_rn_gbl_env icxt,
802 tcg_type_env = ic_type_env icxt,
803 tcg_inst_env = extendInstEnvList (tcg_inst_env env) dfuns }) $
805 updLclEnv (\env -> env { tcl_rdr = ic_rn_local_env icxt }) $
807 do { traceTc (text "setIC" <+> ppr (ic_type_env icxt))
814 -> InteractiveContext
816 -> IO (Maybe (InteractiveContext, [Name], LHsExpr Id))
817 -- The returned [Name] is the same as the input except for
818 -- ExprStmt, in which case the returned [Name] is [itName]
820 -- The returned TypecheckedHsExpr is of type IO [ () ],
821 -- a list of the bound values, coerced to ().
823 tcRnStmt hsc_env ictxt rdr_stmt
824 = initTcPrintErrors hsc_env iNTERACTIVE $
825 setInteractiveContext hsc_env ictxt $ do {
827 -- Rename; use CmdLineMode because tcRnStmt is only used interactively
828 (([rn_stmt], _), fvs) <- rnStmts DoExpr [rdr_stmt] (return ((), emptyFVs)) ;
829 traceRn (text "tcRnStmt" <+> vcat [ppr rdr_stmt, ppr rn_stmt, ppr fvs]) ;
832 -- The real work is done here
833 (bound_ids, tc_expr) <- mkPlan rn_stmt ;
834 zonked_expr <- zonkTopLExpr tc_expr ;
835 zonked_ids <- zonkTopBndrs bound_ids ;
837 -- None of the Ids should be of unboxed type, because we
838 -- cast them all to HValues in the end!
839 mappM bad_unboxed (filter (isUnLiftedType . idType) zonked_ids) ;
841 traceTc (text "tcs 1") ;
842 let { -- (a) Make all the bound ids "global" ids, now that
843 -- they're notionally top-level bindings. This is
844 -- important: otherwise when we come to compile an expression
845 -- using these ids later, the byte code generator will consider
846 -- the occurrences to be free rather than global.
848 -- (b) Tidy their types; this is important, because :info may
849 -- ask to look at them, and :info expects the things it looks
850 -- up to have tidy types
851 global_ids = map globaliseAndTidy zonked_ids ;
853 -- Update the interactive context
854 rn_env = ic_rn_local_env ictxt ;
855 type_env = ic_type_env ictxt ;
857 bound_names = map idName global_ids ;
858 new_rn_env = extendLocalRdrEnv rn_env bound_names ;
860 -- Remove any shadowed bindings from the type_env;
861 -- they are inaccessible but might, I suppose, cause
862 -- a space leak if we leave them there
863 shadowed = [ n | name <- bound_names,
864 let rdr_name = mkRdrUnqual (nameOccName name),
865 Just n <- [lookupLocalRdrEnv rn_env rdr_name] ] ;
867 filtered_type_env = delListFromNameEnv type_env shadowed ;
868 new_type_env = extendTypeEnvWithIds filtered_type_env global_ids ;
870 new_ic = ictxt { ic_rn_local_env = new_rn_env,
871 ic_type_env = new_type_env }
874 dumpOptTcRn Opt_D_dump_tc
875 (vcat [text "Bound Ids" <+> pprWithCommas ppr global_ids,
876 text "Typechecked expr" <+> ppr zonked_expr]) ;
878 returnM (new_ic, bound_names, zonked_expr)
881 bad_unboxed id = addErr (sep [ptext SLIT("GHCi can't bind a variable of unlifted type:"),
882 nest 2 (ppr id <+> dcolon <+> ppr (idType id))])
884 globaliseAndTidy :: Id -> Id
886 -- Give the Id a Global Name, and tidy its type
887 = setIdType (globaliseId VanillaGlobal id) tidy_type
889 tidy_type = tidyTopType (idType id)
892 Here is the grand plan, implemented in tcUserStmt
894 What you type The IO [HValue] that hscStmt returns
895 ------------- ------------------------------------
896 let pat = expr ==> let pat = expr in return [coerce HVal x, coerce HVal y, ...]
899 pat <- expr ==> expr >>= \ pat -> return [coerce HVal x, coerce HVal y, ...]
902 expr (of IO type) ==> expr >>= \ it -> return [coerce HVal it]
903 [NB: result not printed] bindings: [it]
905 expr (of non-IO type, ==> let it = expr in print it >> return [coerce HVal it]
906 result showable) bindings: [it]
908 expr (of non-IO type,
909 result not showable) ==> error
913 ---------------------------
914 type PlanResult = ([Id], LHsExpr Id)
915 type Plan = TcM PlanResult
917 runPlans :: [Plan] -> TcM PlanResult
918 -- Try the plans in order. If one fails (by raising an exn), try the next.
919 -- If one succeeds, take it.
920 runPlans [] = panic "runPlans"
922 runPlans (p:ps) = tryTcLIE_ (runPlans ps) p
925 mkPlan :: LStmt Name -> TcM PlanResult
926 mkPlan (L loc (ExprStmt expr _ _)) -- An expression typed at the prompt
927 = do { uniq <- newUnique -- is treated very specially
928 ; let fresh_it = itName uniq
929 the_bind = L loc $ mkFunBind (L loc fresh_it) matches
930 matches = [mkMatch [] expr emptyLocalBinds]
931 let_stmt = L loc $ LetStmt (HsValBinds (ValBindsOut [(NonRecursive,unitBag the_bind)] []))
932 bind_stmt = L loc $ BindStmt (nlVarPat fresh_it) expr
933 (HsVar bindIOName) noSyntaxExpr
934 print_it = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar fresh_it))
935 (HsVar thenIOName) placeHolderType
938 -- [it <- e; print it] but not if it::()
940 -- [let it = e; print it]
941 ; runPlans [ -- Plan A
942 do { stuff@([it_id], _) <- tcGhciStmts [bind_stmt, print_it]
943 ; it_ty <- zonkTcType (idType it_id)
944 ; ifM (isUnitTy it_ty) failM
947 -- Plan B; a naked bind statment
948 tcGhciStmts [bind_stmt],
950 -- Plan C; check that the let-binding is typeable all by itself.
951 -- If not, fail; if so, try to print it.
952 -- The two-step process avoids getting two errors: one from
953 -- the expression itself, and one from the 'print it' part
954 -- This two-step story is very clunky, alas
955 do { checkNoErrs (tcGhciStmts [let_stmt])
956 --- checkNoErrs defeats the error recovery of let-bindings
957 ; tcGhciStmts [let_stmt, print_it] }
960 mkPlan stmt@(L loc (BindStmt {}))
961 | [L _ v] <- collectLStmtBinders stmt -- One binder, for a bind stmt
962 = do { let print_v = L loc $ ExprStmt (nlHsApp (nlHsVar printName) (nlHsVar v))
963 (HsVar thenIOName) placeHolderType
965 -- [stmt; print v] but not if v::()
967 ; runPlans [do { stuff@([v_id], _) <- tcGhciStmts [stmt, print_v]
968 ; v_ty <- zonkTcType (idType v_id)
969 ; ifM (isUnitTy v_ty || not (isTauTy v_ty)) failM
977 ---------------------------
978 tcGhciStmts :: [LStmt Name] -> TcM PlanResult
980 = do { ioTyCon <- tcLookupTyCon ioTyConName ;
981 ret_id <- tcLookupId returnIOName ; -- return @ IO
983 io_ty = mkTyConApp ioTyCon [] ;
984 ret_ty = mkListTy unitTy ;
985 io_ret_ty = mkTyConApp ioTyCon [ret_ty] ;
987 names = map unLoc (collectLStmtsBinders stmts) ;
989 -- mk_return builds the expression
990 -- returnIO @ [()] [coerce () x, .., coerce () z]
992 -- Despite the inconvenience of building the type applications etc,
993 -- this *has* to be done in type-annotated post-typecheck form
994 -- because we are going to return a list of *polymorphic* values
995 -- coerced to type (). If we built a *source* stmt
996 -- return [coerce x, ..., coerce z]
997 -- then the type checker would instantiate x..z, and we wouldn't
998 -- get their *polymorphic* values. (And we'd get ambiguity errs
999 -- if they were overloaded, since they aren't applied to anything.)
1000 mk_return ids = nlHsApp (mkHsTyApp ret_id [ret_ty])
1001 (noLoc $ ExplicitList unitTy (map mk_item ids)) ;
1002 mk_item id = nlHsApp (noLoc $ unsafeCoerce)
1005 unsafeCoerce x = Cast x (mkUnsafeCoercion [idType id, unitTy])
1008 -- OK, we're ready to typecheck the stmts
1009 traceTc (text "tcs 2") ;
1010 ((tc_stmts, ids), lie) <- getLIE $
1011 tcStmts DoExpr (tcDoStmt io_ty) stmts io_ret_ty $ \ _ ->
1012 mappM tcLookupId names ;
1013 -- Look up the names right in the middle,
1014 -- where they will all be in scope
1016 -- Simplify the context
1017 const_binds <- checkNoErrs (tcSimplifyInteractive lie) ;
1018 -- checkNoErrs ensures that the plan fails if context redn fails
1020 return (ids, mkHsDictLet const_binds $
1021 noLoc (HsDo DoExpr tc_stmts (mk_return ids) io_ret_ty))
1026 tcRnExpr just finds the type of an expression
1030 -> InteractiveContext
1033 tcRnExpr hsc_env ictxt rdr_expr
1034 = initTcPrintErrors hsc_env iNTERACTIVE $
1035 setInteractiveContext hsc_env ictxt $ do {
1037 (rn_expr, fvs) <- rnLExpr rdr_expr ;
1040 -- Now typecheck the expression;
1041 -- it might have a rank-2 type (e.g. :t runST)
1042 ((tc_expr, res_ty), lie) <- getLIE (tcInferRho rn_expr) ;
1043 ((qtvs, _, dict_ids), lie_top) <- getLIE (tcSimplifyInfer smpl_doc (tyVarsOfType res_ty) lie) ;
1044 tcSimplifyInteractive lie_top ;
1045 qtvs' <- mappM zonkQuantifiedTyVar qtvs ;
1047 let { all_expr_ty = mkForAllTys qtvs' $
1048 mkFunTys (map idType dict_ids) $
1050 zonkTcType all_expr_ty
1053 smpl_doc = ptext SLIT("main expression")
1056 tcRnType just finds the kind of a type
1060 -> InteractiveContext
1063 tcRnType hsc_env ictxt rdr_type
1064 = initTcPrintErrors hsc_env iNTERACTIVE $
1065 setInteractiveContext hsc_env ictxt $ do {
1067 rn_type <- rnLHsType doc rdr_type ;
1070 -- Now kind-check the type
1071 (ty', kind) <- kcHsType rn_type ;
1075 doc = ptext SLIT("In GHCi input")
1081 %************************************************************************
1083 More GHCi stuff, to do with browsing and getting info
1085 %************************************************************************
1089 -- ASSUMES that the module is either in the HomePackageTable or is
1090 -- a package module with an interface on disk. If neither of these is
1091 -- true, then the result will be an error indicating the interface
1092 -- could not be found.
1093 getModuleExports :: HscEnv -> Module -> IO (Messages, Maybe NameSet)
1094 getModuleExports hsc_env mod
1095 = initTc hsc_env HsSrcFile iNTERACTIVE (tcGetModuleExports mod)
1097 tcGetModuleExports :: Module -> TcM NameSet
1098 tcGetModuleExports mod = do
1099 let doc = ptext SLIT("context for compiling statements")
1100 iface <- initIfaceTcRn $ loadSysInterface doc mod
1101 loadOrphanModules (dep_orphs (mi_deps iface))
1102 -- Load any orphan-module interfaces,
1103 -- so their instances are visible
1104 ifaceExportNames (mi_exports iface)
1106 tcRnLookupRdrName :: HscEnv -> RdrName -> IO (Maybe [Name])
1107 tcRnLookupRdrName hsc_env rdr_name
1108 = initTcPrintErrors hsc_env iNTERACTIVE $
1109 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1110 lookup_rdr_name rdr_name
1112 lookup_rdr_name rdr_name = do {
1113 -- If the identifier is a constructor (begins with an
1114 -- upper-case letter), then we need to consider both
1115 -- constructor and type class identifiers.
1116 let { rdr_names = dataTcOccs rdr_name } ;
1118 -- results :: [Either Messages Name]
1119 results <- mapM (tryTcErrs . lookupOccRn) rdr_names ;
1121 traceRn (text "xx" <+> vcat [ppr rdr_names, ppr (map snd results)]);
1122 -- The successful lookups will be (Just name)
1123 let { (warns_s, good_names) = unzip [ (msgs, name)
1124 | (msgs, Just name) <- results] ;
1125 errs_s = [msgs | (msgs, Nothing) <- results] } ;
1127 -- Fail if nothing good happened, else add warnings
1128 if null good_names then
1129 -- No lookup succeeded, so
1130 -- pick the first error message and report it
1131 -- ToDo: If one of the errors is "could be Foo.X or Baz.X",
1132 -- while the other is "X is not in scope",
1133 -- we definitely want the former; but we might pick the latter
1134 do { addMessages (head errs_s) ; failM }
1135 else -- Add deprecation warnings
1136 mapM_ addMessages warns_s ;
1142 tcRnLookupName :: HscEnv -> Name -> IO (Maybe TyThing)
1143 tcRnLookupName hsc_env name
1144 = initTcPrintErrors hsc_env iNTERACTIVE $
1145 setInteractiveContext hsc_env (hsc_IC hsc_env) $
1149 tcRnGetInfo :: HscEnv
1151 -> IO (Maybe (TyThing, Fixity, [Instance]))
1153 -- Used to implemnent :info in GHCi
1155 -- Look up a RdrName and return all the TyThings it might be
1156 -- A capitalised RdrName is given to us in the DataName namespace,
1157 -- but we want to treat it as *both* a data constructor
1158 -- *and* as a type or class constructor;
1159 -- hence the call to dataTcOccs, and we return up to two results
1160 tcRnGetInfo hsc_env name
1161 = initTcPrintErrors hsc_env iNTERACTIVE $
1162 let ictxt = hsc_IC hsc_env in
1163 setInteractiveContext hsc_env ictxt $ do
1165 -- Load the interface for all unqualified types and classes
1166 -- That way we will find all the instance declarations
1167 -- (Packages have not orphan modules, and we assume that
1168 -- in the home package all relevant modules are loaded.)
1169 loadUnqualIfaces ictxt
1171 thing <- tcLookupGlobal name
1172 fixity <- lookupFixityRn name
1173 ispecs <- lookupInsts (icPrintUnqual ictxt) thing
1174 return (thing, fixity, ispecs)
1177 lookupInsts :: PrintUnqualified -> TyThing -> TcM [Instance]
1178 -- Filter the instances by the ones whose tycons (or clases resp)
1179 -- are in scope unqualified. Otherwise we list a whole lot too many!
1180 lookupInsts print_unqual (AClass cls)
1181 = do { inst_envs <- tcGetInstEnvs
1183 | ispec <- classInstances inst_envs cls
1184 , plausibleDFun print_unqual (instanceDFunId ispec) ] }
1186 lookupInsts print_unqual (ATyCon tc)
1187 = do { eps <- getEps -- Load all instances for all classes that are
1188 -- in the type environment (which are all the ones
1189 -- we've seen in any interface file so far)
1190 ; (pkg_ie, home_ie) <- tcGetInstEnvs -- Search all
1192 | ispec <- instEnvElts home_ie ++ instEnvElts pkg_ie
1193 , let dfun = instanceDFunId ispec
1195 , plausibleDFun print_unqual dfun ] }
1197 relevant df = tc_name `elemNameSet` tyClsNamesOfDFunHead (idType df)
1198 tc_name = tyConName tc
1200 lookupInsts print_unqual other = return []
1202 plausibleDFun print_unqual dfun -- Dfun involving only names that print unqualified
1203 = all ok (nameSetToList (tyClsNamesOfType (idType dfun)))
1205 ok name | isBuiltInSyntax name = True
1206 | isExternalName name =
1207 isNothing $ fst print_unqual (nameModule name)
1211 loadUnqualIfaces :: InteractiveContext -> TcM ()
1212 -- Load the home module for everything that is in scope unqualified
1213 -- This is so that we can accurately report the instances for
1215 loadUnqualIfaces ictxt
1217 mapM_ (loadSysInterface doc) (moduleSetElts (mkModuleSet unqual_mods))
1219 unqual_mods = [ nameModule name
1220 | gre <- globalRdrEnvElts (ic_rn_gbl_env ictxt),
1221 let name = gre_name gre,
1222 not (isInternalName name),
1223 isTcOcc (nameOccName name), -- Types and classes only
1224 unQualOK gre ] -- In scope unqualified
1225 doc = ptext SLIT("Need interface for module whose export(s) are in scope unqualified")
1229 %************************************************************************
1233 %************************************************************************
1236 rnDump :: SDoc -> TcRn ()
1237 -- Dump, with a banner, if -ddump-rn
1238 rnDump doc = do { dumpOptTcRn Opt_D_dump_rn (mkDumpDoc "Renamer" doc) }
1240 tcDump :: TcGblEnv -> TcRn ()
1242 = do { dflags <- getDOpts ;
1244 -- Dump short output if -ddump-types or -ddump-tc
1245 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1246 (dumpTcRn short_dump) ;
1248 -- Dump bindings if -ddump-tc
1249 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump)
1252 short_dump = pprTcGblEnv env
1253 full_dump = pprLHsBinds (tcg_binds env)
1254 -- NB: foreign x-d's have undefined's in their types;
1255 -- hence can't show the tc_fords
1258 = do { dflags <- getDOpts ;
1259 ifM (dopt Opt_D_dump_types dflags || dopt Opt_D_dump_tc dflags)
1260 (dumpTcRn (pprModGuts mod_guts)) ;
1262 -- Dump bindings if -ddump-tc
1263 dumpOptTcRn Opt_D_dump_tc (mkDumpDoc "Typechecker" full_dump) }
1265 full_dump = pprCoreBindings (mg_binds mod_guts)
1267 -- It's unpleasant having both pprModGuts and pprModDetails here
1268 pprTcGblEnv :: TcGblEnv -> SDoc
1269 pprTcGblEnv (TcGblEnv { tcg_type_env = type_env,
1270 tcg_insts = dfun_ids,
1272 tcg_imports = imports })
1273 = vcat [ ppr_types dfun_ids type_env
1274 , ppr_insts dfun_ids
1275 , vcat (map ppr rules)
1276 , ppr_gen_tycons (typeEnvTyCons type_env)
1277 , ptext SLIT("Dependent modules:") <+> ppr (eltsUFM (imp_dep_mods imports))
1278 , ptext SLIT("Dependent packages:") <+> ppr (imp_dep_pkgs imports)]
1280 pprModGuts :: ModGuts -> SDoc
1281 pprModGuts (ModGuts { mg_types = type_env,
1283 = vcat [ ppr_types [] type_env,
1287 ppr_types :: [Instance] -> TypeEnv -> SDoc
1288 ppr_types ispecs type_env
1289 = text "TYPE SIGNATURES" $$ nest 4 (ppr_sigs ids)
1291 dfun_ids = map instanceDFunId ispecs
1292 ids = [id | id <- typeEnvIds type_env, want_sig id]
1293 want_sig id | opt_PprStyle_Debug = True
1294 | otherwise = isLocalId id &&
1295 isExternalName (idName id) &&
1296 not (id `elem` dfun_ids)
1297 -- isLocalId ignores data constructors, records selectors etc.
1298 -- The isExternalName ignores local dictionary and method bindings
1299 -- that the type checker has invented. Top-level user-defined things
1300 -- have External names.
1302 ppr_insts :: [Instance] -> SDoc
1303 ppr_insts [] = empty
1304 ppr_insts ispecs = text "INSTANCES" $$ nest 2 (pprInstances ispecs)
1306 ppr_sigs :: [Var] -> SDoc
1308 -- Print type signatures; sort by OccName
1309 = vcat (map ppr_sig (sortLe le_sig ids))
1311 le_sig id1 id2 = getOccName id1 <= getOccName id2
1312 ppr_sig id = ppr id <+> dcolon <+> ppr (tidyTopType (idType id))
1314 ppr_rules :: [CoreRule] -> SDoc
1315 ppr_rules [] = empty
1316 ppr_rules rs = vcat [ptext SLIT("{-# RULES"),
1317 nest 4 (pprRules rs),
1320 ppr_gen_tycons [] = empty
1321 ppr_gen_tycons tcs = vcat [ptext SLIT("Tycons with generics:"),
1322 nest 2 (fsep (map ppr (filter tyConHasGenerics tcs)))]